|
Description
|
FULL PRODUCT VERSION :
1.6.0-b105
ADDITIONAL OS VERSION INFORMATION :
customer Windows XP [Version 5.1.2600]
A DESCRIPTION OF THE PROBLEM :
final long stack variable gets corrupted when FileChannel read is interrupted
STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
run the main method in provided source code
EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
final long variable value remains constant
ACTUAL -
final long variable value gets corrupted during program execution
REPRODUCIBILITY :
This bug can be reproduced always.
---------- BEGIN SOURCE ----------
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.channels.ByteChannel;
import java.security.MessageDigest;
import java.util.Date;
import java.util.Random;
public class CorruptFinalLong {
private static final Random random = new Random();
private static void createFileIfNeeded(File file) throws IOException {
if (!file.exists()) {
int bufSize = 1000000;
int rounds = 50;
System.out.println("writing random file " + file + " of size " + (bufSize * rounds)
+ " bytes");
byte[] buf = new byte[bufSize];
OutputStream out = new BufferedOutputStream(new FileOutputStream(file), 65536);
for (int i = 0; i < rounds; i++) {
random.nextBytes(buf);
out.write(buf);
}
out.close();
}
}
public static void main(String[] args) throws Exception {
System.setErr(System.out);
String[] props = new String[] { "java.vm.version", "java.vm.name", "sun.os.patch.level",
"java.runtime.version", "java.vm.version", "os.arch", "os.name",
"java.specification.version", "java.vm.specification.version",
"java.specification.vendor", "java.version" };
for (String p : props) {
System.out.printf("%30s: %s", p, System.getProperty(p));
System.out.println();
}
System.out.println();
final File file = new File("random.dat");
createFileIfNeeded(file);
final Thread t = Thread.currentThread();
new Thread(new Runnable() {
public void run() {
try {
Thread.sleep(1000);
System.out.println("\tabout to interrupt thread '" + t + "' from thread '"
+ Thread.currentThread() + "'");
t.interrupt();
} catch (InterruptedException e) {
System.out.println("\tinterrupted in thread");
e.printStackTrace();
}
}
}).start();
final long start = System.currentTimeMillis();
System.out.println("started at " + new Date(start) + " (" + start + " ms)");
System.out.println();
MessageDigest md = MessageDigest.getInstance("MD5");
ByteChannel channel = new FileInputStream(file).getChannel();
try {
int cap = 10;
ByteBuffer byteBuffer = ByteBuffer.allocateDirect(cap);
byte[] local = new byte[cap];
long lastRead = 0;
boolean eof = false;
while (!eof) {
byteBuffer.rewind();
int bytesReadThisTime = channel.read(byteBuffer);
if (bytesReadThisTime == -1) {
eof = true;
} else {
// totalRead += bytesReadThisTime;
byteBuffer.rewind();
byteBuffer.get(local, 0, bytesReadThisTime);
md.update(local, 0, bytesReadThisTime);
if (System.currentTimeMillis() - lastRead > 1000) {
lastRead = System.currentTimeMillis();
}
}
}
} catch (Exception e) {
if (Thread.interrupted()) {
System.out.println("\t********* IO was interrupted in thread '"
+ Thread.currentThread() + "': " + e);
} else {
System.out.println("\texception: " + e);
}
} finally {
channel.close();
}
System.out.println();
System.out
.println("the following line should be identical to the similar one above, since variable 'start' is final:");
System.out.println("started at " + new Date(start) + " (" + start + " ms)");
}
}
---------- END SOURCE ----------
CUSTOMER SUBMITTED WORKAROUND :
none --- aside from reverting to java 5.0
Posted Date : 2007-01-11 10:56:02.0
|
